High-performance low-carbon electrode material based on cigarette end recycling and preparation and application thereof

Abstract

The invention discloses a high-performance low-carbon electrode material based on cigarette end recycling and preparation and application thereof, and relates to the technical field of waste cigarette end recycling and electrode materials. The invention particularly relates to a green method for preparing a high-performance low-carbon electrode material by using waste cigarette ends and an energy storage application of the electrode material in a supercapacitor. Cellulose acetate in cigarette ends is converted into a porous carbon material with a high specific surface area through ultrasonic microwave co-processing, gradient carbonization and plasma activation technologies, and efficient preparation and cyclic utilization of an electrode material are realized by combining a natural template modification process.

Description

Technical Field

[0001] This invention relates to the fields of waste cigarette butt recycling technology and electrode materials technology, and particularly to high-performance, low-carbon electrode materials based on cigarette butt recycling, their preparation, and applications. Background Technology

[0002] The main component of cigarette filter material is cellulose acetate (polypropylene tow), which has the function of adsorbing tar and harmful particles. Globally, approximately 4.5 trillion cigarette butts are produced annually, of which cellulose acetate filters (accounting for >90%) contribute to soil microplastic pollution due to their non-degradability.

[0003] Traditional waste disposal methods, such as incineration or landfill, result in high carbon emissions and resource waste. Over 500,000 tons of cigarette butts accumulate in my country's urban waste annually, highlighting the urgent need for efficient resource recovery solutions.

[0004] Existing technologies for recycling and reusing cigarette butts are mostly limited to the development of adsorption materials, lacking high-value-added energy storage applications. Furthermore, the recycling process suffers from severe exhaust pollution, unrecovered metal components, and difficulties in achieving closed-loop recycling. These factors significantly hinder the recycling and reuse of cigarette butts and limit their application areas. Summary of the Invention

[0005] This invention provides a high-performance, low-carbon electrode material based on cigarette butt recycling, its preparation, and its application. The invention involves processing waste acetate fiber from cigarette butts using a special process to create a porous carbon material. This porous carbon material then serves as a template, allowing porous CaCO3 micropowder to be adsorbed onto its surface. Finally, Fe3O4 nanoparticles are adsorbed onto the surface of the porous carbon material, ultimately forming the electrode material. This electrode material exhibits higher specific capacitance and better charge-discharge cycle performance. Specifically, this is achieved through the following techniques.

[0006] This invention provides a method for preparing a high-performance, low-carbon electrode material based on cigarette butt recycling, comprising the following steps:

[0007] Remove impurities from cigarette butts to obtain cellulose acetate waste;

[0008] The cellulose acetate waste was pre-oxidized at 240-280°C for 1-4 hours in an oxygen-containing atmosphere.

[0009] In an inert atmosphere, heat to 300-400℃ for 55-65 min, then further heat to 550-600℃ for 85-95 min;

[0010] Porous carbon materials are obtained by plasma treatment for 30-40 minutes under an argon atmosphere with a power of 300-400 W and an average core temperature of 50-120℃.

[0011] Take porous CaCO3 micro powder and porous carbon materials and add Fe 3+ The active material is obtained by immersion in a salt solution, drying, and microwave treatment.

[0012] The active material, conductive carbon black, and PVDF are added to N-methylpyrrolidone to prepare a conductive paste, which is then coated onto a current collector to prepare the high-performance low-carbon electrode material.

[0013] Furthermore, the size of the cellulose acetate waste is 40-150 mesh.

[0014] Further, the first method for removing impurities from cigarette butts is as follows: the cigarette butts are soaked in a 50% (v / v) aqueous ethanol solution, filtered, and the filtered solids are extracted with acetone and then crushed to obtain the cellulose acetate waste.

[0015] Furthermore, the mass-to-volume ratio of the cigarette butt to the 50% ethanol aqueous solution is 0.5-1.5 g / ml.

[0016] Furthermore, a second method for removing impurities from cigarette butts is to crush the cigarette butts and then subject them to ultrasonic-microwave treatment to obtain the cellulose acetate waste.

[0017] Furthermore, the ultrasonic-microwave treatment method is as follows: ultrasonic power 250-350 W, frequency 35-45 kHz, microwave power 350-450 W, temperature 55-65℃, treatment time 40-60 min.

[0018] Furthermore, a third method for removing impurities from cigarette butts is to soak the cigarette butts in a toluene-ethanol solution, followed by ultrasonication, vacuum filtration, drying, and pulverization to obtain the cellulose acetate waste.

[0019] Furthermore, the volume ratio of toluene to ethanol in the toluene-ethanol solution is (1-3):1, and the ultrasonic treatment method is to treat at 45-55℃ for 30-40 min.

[0020] This invention removes paper scraps, adhesives, and other contaminants from cigarette butts by performing the above-mentioned impurity removal treatment. The pulverized cellulose acetate is also more conducive to subsequent reactions.

[0021] Furthermore, the cellulose acetate waste is pre-oxidized at 250°C for 3 hours in an oxygen-containing atmosphere.

[0022] Furthermore, the temperature was raised to 400°C for 60 min in an inert atmosphere, and then further raised to 600°C for 90 min.

[0023] Furthermore, under an argon atmosphere, plasma treatment was performed for 35 minutes at a power of 400 W and an average core temperature of 100°C to obtain porous carbon materials.

[0024] Furthermore, with Fe 3+ Fe in salt solution 3+ Assuming a concentration of 0.5 mol / L, the concentration of porous CaCO3 micropowder in the system is 0.05-0.15 g / ml, and the concentration of porous carbon material is 0.1 g / ml.

[0025] Furthermore, with Fe 3+ Fe in salt solution 3+ Assuming a concentration of 0.5 mol / L, the concentration of porous CaCO3 micropowder in the system is 0.1 g / ml.

[0026] Furthermore, porous CaCO3 micro powder and porous carbon materials were added with Fe. 3+ Immerse in salt water solution for 1-2 hours;

[0027] Furthermore, the immersion treatment time is 2 hours.

[0028] By performing the gradient carbonization treatment in a protective atmosphere, cellulose acetate gradually removes volatiles and carbonizes in a gradually increasing or decreasing temperature environment. This avoids the destruction of the cellulose acetate structure due to rapid temperature changes or local overheating or overcooling, and can prevent structural collapse caused by local overheating. This ensures the stability and controllability of the carbonization process and guarantees the final formation of a stable porous structure.

[0029] Next, plasma treatment is performed under an argon atmosphere to etch abundant pores into the carbon material. This process also allows the plasma to react with molecules on the cellulose acetate surface, introducing new functional groups such as hydroxyl, carboxyl, and amino groups. The introduction of these functional groups enhances the hydrophilicity, polarity, and chemical reactivity of the cellulose acetate surface, making it easier to react chemically with other substances or form chemical bonds, thereby improving the compatibility and bonding strength of cellulose acetate with other materials. By adjusting the activation zone temperature, gas flow rate, and material residence time, the pore size distribution (micropore-to-mesopore ratio) can be precisely controlled.

[0030] Finally, porous CaCO3 micro powder and porous carbon materials were added to Fe. 3+Immersion in a salt solution followed by microwave treatment directly targets the polar molecules within the material, causing them to vibrate at high speed and generate frictional heat. This allows for the generation of a large number of Fe3O4 nanoparticles in a short time at relatively low power, significantly reducing reaction time and improving production efficiency. In contrast, traditional heating methods gradually conduct heat from the outside, which can easily lead to temperature gradients, resulting in uneven heating and longer processing times.

[0031] The present invention also provides a high-performance low-carbon electrode material based on cigarette butt recycling prepared by the above preparation method.

[0032] The present invention also provides an application of the above-mentioned high-performance low-carbon electrode material in the preparation of supercapacitors.

[0033] The present invention also provides a supercapacitor comprising an electrode sheet made of the above-mentioned high-performance low-carbon electrode material.

[0034] Compared with the prior art, the advantages of the present invention are:

[0035] 1. This invention utilizes waste cigarette butts, which undergo impurity removal pretreatment, gradient carbonization, and microwave treatment in sequence. The resulting active material is then used with other necessary raw materials to prepare high-performance low-carbon electrode materials, achieving efficient resource utilization of cigarette butts, reducing microplastic pollution, and lowering the production cost of electrode materials by 58%.

[0036] 2. When supercapacitors are prepared using high-performance low-carbon electrode materials, the combination of porous carbon materials and Fe3O4 modification significantly improves the capacitance performance, cycle life, and rate performance of the supercapacitors. Detailed Implementation

[0037] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] In some embodiments of the present invention, a method for preparing a high-performance, low-carbon electrode material based on cigarette butt recycling is provided, comprising the following steps:

[0039] (1) Remove impurities from cigarette butts to obtain cellulose acetate waste. The final size of the cellulose acetate waste can be controlled to be 40-150 mesh.

[0040] (2) The cellulose acetate waste is pre-oxidized in an oxygen-containing atmosphere at 240-280°C for 1-4 h.

[0041] (3) In an inert atmosphere, heat to 300-400℃ for 55-65 min, and then heat to 550-600℃ for 85-95 min.

[0042] (4) Under an argon atmosphere, plasma treatment is carried out for 30-40 min with a power of 300-400 W and an average core temperature of 50-120℃ to obtain porous carbon materials.

[0043] (5) Using porous CaCO3 micro powder as a template, the porous carbon material is immersed in Fe. 3+ The active material is obtained by impregnation in a salt solution, drying, and microwave treatment.

[0044] (6) The active material, conductive carbon black and PVDF are added to N-methylpyrrolidone to prepare a conductive paste, and the conductive paste is coated on the current collector to prepare the high-performance low-carbon electrode material.

[0045] In the above-described method for preparing high-performance low-carbon electrode materials, the first method for removing impurities from cigarette butts is as follows: the cigarette butts are soaked in a 50% (v / v) aqueous ethanol solution, filtered, and the filtered solid is extracted with acetone and then pulverized to obtain the cellulose acetate waste. For example, the mass-to-volume ratio of the cigarette butts to the 50% (v / v) aqueous ethanol solution is 0.5-1.5 g / ml.

[0046] In the above-mentioned method for preparing high-performance low-carbon electrode materials, the second method for removing impurities from cigarette butts is as follows: the cigarette butts are crushed and then subjected to ultrasonic-microwave treatment to obtain the cellulose acetate waste. For example, the ultrasonic-microwave treatment method is as follows: ultrasonic power 250-350 W, frequency 35-45 kHz, microwave power 350-450 W, temperature 55-65℃, treatment time 40-60 min. Specifically, the ultrasonic-microwave treatment method is as follows: ultrasonic power 300 W, frequency 40 kHz, microwave power 400 W, temperature 60℃, treatment time 45 min.

[0047] The third method for removing impurities from cigarette butts in the above-mentioned method for preparing high-performance low-carbon electrode materials is as follows: The cigarette butts are soaked in a toluene-ethanol solution (toluene and ethanol volume ratio (1-3):1), followed by ultrasonication, vacuum filtration, drying, and pulverization to obtain the cellulose acetate waste. The ultrasonication method involves treating the cigarette butts at 45-55℃ for 30-40 minutes.

[0048] In the above method for preparing high-performance low-carbon electrode materials, the cellulose acetate waste is pre-oxidized at 250°C for 3 hours in an oxygen-containing atmosphere.

[0049] In the above method for preparing high-performance low-carbon electrode materials, the material is heated to 400°C for 60 min in an inert atmosphere, and then further heated to 600°C for 90 min.

[0050] In the above method for preparing high-performance low-carbon electrode materials, plasma treatment is performed for 35 minutes under an argon atmosphere with a power of 400 W and an average core temperature of 100°C to obtain porous carbon materials.

[0051] In the above method for preparing high-performance low-carbon electrode materials, Fe is used. 3+ Fe in salt solution 3+ Assuming a concentration of 0.5 mol / L, the concentration of porous CaCO3 micropowder in the system is 0.5-1.5 g / ml, and the concentration of porous carbon material is 1 g / ml.

[0052] Specifically, the concentration of porous CaCO3 micro powder in the system is 1 g / ml.

[0053] Furthermore, porous CaCO3 micro powder and porous carbon materials were added with Fe. 3+ Immerse in salt water solution for 1-2 hours;

[0054] Specifically, the immersion treatment time is 2 hours.

[0055] Example 1

[0056] 1. The specific steps for preparing the high-performance low-carbon electrode material in this embodiment are as follows:

[0057] (1) Soak the cigarette butts in a 50% ethanol aqueous solution for 30 min, with a mass-to-volume ratio of 1 g / ml;

[0058] The filtered solid was subjected to Soxhlet extraction with acetone at 60°C for 6 hours to obtain 18.5 g of cellulose acetate with a purity of not less than 95%.

[0059] The material was crushed to obtain 100-mesh (approximately 150 μm) cellulose acetate waste.

[0060] (2) Place the cellulose acetate waste powder in a tube furnace and heat it to 250°C at 5°C / min under an oxygen atmosphere, and keep it at the temperature for 3 h.

[0061] (3) In an argon atmosphere, heat to 400℃ for 60 min, then heat to 600℃ for 90 min to complete the gradient carbonization process.

[0062] (4) Under an argon atmosphere, plasma treatment was performed for 35 minutes at a power of 400 W and an average core temperature of about 100 °C to obtain porous carbon material.

[0063] (5) Take waste seashells, calcine at 900℃ for 2 h, and ball mill them to an average particle size of 10 μm to obtain porous CaCO3 micro powder.

[0064] Five g of porous carbon material and five g of porous CaCO3 micro powder (as template) were immersed in 50 mL of 0.5 mol / L Fe(NO3)3 solution for 2 h and dried at 80 °C. The active material was obtained by microwave treatment at 800 W for 15 min.

[0065] In the active material, the loading of Fe3O4 nanoparticles is approximately 12 wt%, and the specific surface area (BTE method) reaches 1250 m². 2 / g, pore volume 0.70 cm³ 3 / g; Pore size distribution: micropores (<2 nm) account for 62%, mesopores (2-50 nm) account for 31%, and macropores (>50 nm) account for 7%.

[0066] (6) The active material, conductive carbon black, and PVDF are mixed evenly at a mass ratio of 8:1:1, and a conductive slurry is prepared using N-methylpyrrolidone as a solvent; the conductive slurry is coated onto a nickel foam current collector (1 cm × 1 cm, 0.8 mm thick) to prepare an active material (i.e., a porous carbon material composite material loaded with Fe3O4) with a loading of approximately 3 mg / cm. 2 High-performance, low-carbon electrode materials.

[0067] 2. Performance testing of high-performance low-carbon electrode materials

[0068] The test was conducted in a 6 mol / L KOH electrolyte using a three-electrode system, with high-performance low-carbon electrode material as the test electrode, Hg / HgO as the reference electrode, and a platinum sheet as the counter electrode.

[0069] The fabricated supercapacitor exhibits a high energy density of 20.5 W / kg and a power density of 520 W / kg. At a current density of 1 A / g, the specific capacitance of the high-performance low-carbon electrode material is 412 F / g; increasing the current density to 5 A / g, the specific capacitance is 328 F / g with a retention rate of 78.9%; increasing the current density to 10 A / g, the specific capacitance is 276 F / g with a retention rate of 66.5%, and the voltage retention rate after 24 h is 88.3%. Within the range of 10 A / g to 20 A / g, the capacitance retention rate is >57%.

[0070] After 5000 cycles at a current density of 0.5 A / g, the capacity retention is 90%. After 10000 cycles at a current density of 1 A / g, the capacity retention is 85%; internal resistance (AC impedance test) is 1.2 Ω·cm.2 .

[0071] Example 2

[0072] 1. The specific steps for preparing the high-performance low-carbon electrode material in this embodiment are as follows:

[0073] (1) Crush the waste cigarette butt raw material to 100-150 mesh and put it into an ultrasonic-microwave reactor. Under the conditions of ultrasonic power 300W, frequency 40 kHz, microwave power 400 W, and temperature 60℃, process for 45 min.

[0074] After treatment, the impurity removal rate is >85%, and the cellulose acetate recovery rate is increased to 22% (18% higher than the traditional grinding method).

[0075] (2) Place the cellulose acetate waste powder in a tube furnace and heat it to 280°C at 5°C / min under an oxygen atmosphere, and keep it at the temperature for 1 h.

[0076] (3) In an argon atmosphere, heat to 300℃ for 65 min, then heat to 550℃ for 95 min to complete the gradient carbonization process.

[0077] (4) Under an argon atmosphere, plasma treatment was performed for 30 min at a power of 300 W and an average core temperature of about 120 °C to obtain porous carbon material.

[0078] (5) Take waste seashells, calcine at 900℃ for 2 h, and ball mill them to an average particle size of 10 μm to obtain porous CaCO3 micro powder.

[0079] 7.5 g of porous carbon material and 5 g of porous CaCO3 micro powder (as template) were immersed in 50 mL of 0.5 mol / L Fe(NO3)3 solution for 1 h and dried at 80 °C. The active material was obtained by microwave treatment at 800 W for 15 min.

[0080] In the active material, the loading of Fe3O4 nanoparticles is approximately 12.3 wt%, and the specific surface area (BTE method) reaches 1265 m². 2 / g, pore volume 0.715 cm³ 3 / g; Pore size distribution: micropores (<2 nm) account for 63%, mesopores (2-50 nm) account for 30%, and macropores (>50 nm) account for 7%.

[0081] (6) The active material, conductive carbon black, and PVDF are mixed evenly at a mass ratio of 8:1:1, and a conductive slurry is prepared using N-methylpyrrolidone as a solvent; the conductive slurry is coated onto a nickel foam current collector (1 cm × 1 cm) to obtain an active material loading of approximately 5 mg / cm. 2High-performance, low-carbon electrode materials.

[0082] 2. Performance testing of high-performance low-carbon electrode materials

[0083] The test was conducted in a 6 mol / L KOH electrolyte using a two-electrode system, with a high-performance low-carbon electrode material as the test electrode, Hg / HgO as the reference electrode, and a platinum sheet as the counter electrode.

[0084] The fabricated supercapacitor exhibits a high energy density of 21.2 W h / kg and a power density of 535 W / kg. At a current density of 1 A / g, the specific capacitance of the high-performance low-carbon electrode material is 425 F / g; increasing the current density to 5 A / g, the specific capacitance is 348 F / g with a retention rate of 81.9%; increasing the current density to 10 A / g, the specific capacitance is 288 F / g with a retention rate of 67.8%, and the voltage retention rate after 24 h is 90.1%. Within the range of 10 A / g to 20 A / g, the capacitance retention rate is >58%.

[0085] After 5000 cycles at a current density of 0.5 A / g, the capacity retention was 91.5%. After 10000 cycles at a current density of 1 A / g, the capacity retention was 89%, demonstrating good cycle stability; the internal resistance (AC impedance test) was 1.2 Ω·cm. 2 .

[0086] Example 3

[0087] 1. The specific steps for preparing the high-performance low-carbon electrode material in this embodiment are as follows:

[0088] (1) Soak the cigarette butts in a toluene-ethanol solution (2:1, v / v), sonicate at 50°C for 35 min, vacuum filter, dry at 75°C for 4 h, and pulverize to 150 mesh (particle size about 100 μm) to obtain cellulose acetate waste.

[0089] (2) Place the cellulose acetate waste powder in a tube furnace and heat it to 240°C at 1°C / min under an oxygen atmosphere, and keep it at the temperature for 4 h.

[0090] (3) In an argon atmosphere, heat to 400℃ for 55 min, then heat to 600℃ for 85 min to complete the gradient carbonization process.

[0091] (4) Under an argon atmosphere, plasma treatment was performed for 40 min at a power of 400 W and an average core temperature of about 50 °C to obtain porous carbon material.

[0092] (5) Take waste seashells, calcine at 900℃ for 2 h, and ball mill them to an average particle size of 10 μm to obtain porous CaCO3 micro powder.

[0093] 2.5 g of porous carbon material and 5 g of porous CaCO3 micro powder (as template) were immersed in 50 mL of 0.5 mol / L Fe(NO3)3 solution for 2 h and dried at 80 °C. The mixture was then microwaved at 800 W for 15 min to obtain 8.1 g of active material.

[0094] In the active material, the loading of Fe3O4 nanoparticles is approximately 11.7 wt%, and the specific surface area (BTE method) reaches 1225 m². 2 / g, pore volume 0.685 cm³ 3 / g; Pore size distribution: micropores (<2 nm) account for 60%, mesopores (2-50 nm) account for 32%, and macropores (>50 nm) account for 8%.

[0095] (6) The active material, acetylene black, and PTFE emulsion were mixed uniformly at a mass ratio of 7:1.5:1.5 to prepare a conductive paste; the conductive paste was coated onto a titanium foil current collector (thickness 0.1 mm), and activated by cyclic voltammetry in a 6 mol / L KOH solution (50 mV / s, 50 cycles) to obtain an active material loading of approximately 4.5 mg / cm³. 2 High-performance, low-carbon electrode materials.

[0096] 2. Performance testing of high-performance low-carbon electrode materials

[0097] The test was conducted in a 6 mol / L KOH electrolyte using a three-electrode system, with high-performance low-carbon electrode material as the test electrode, Hg / HgO as the reference electrode, and a platinum sheet as the counter electrode.

[0098] The fabricated supercapacitor exhibits a high energy density of 19.6 W / kg and a power density of 500 W / kg. At a current density of 1 A / g, the specific capacitance of the high-performance low-carbon electrode material is 398 F / g; increasing the current density to 5 A / g, the specific capacitance is 320 F / g with a retention rate of 80.4%; increasing the current density to 10 A / g, the specific capacitance is 268 F / g with a retention rate of 67.3%, and the voltage retention rate after 24 h is 87.6%. Within the range of 10 A / g to 20 A / g, the capacitance retention rate is >56%.

[0099] After 5000 cycles at a current density of 0.5 A / g, the capacity retention was 89.2%. After 10000 cycles at a current density of 1 A / g, the capacity retention was 84.5%; the internal resistance (AC impedance test) was 1.25 Ω·cm. 2 .

[0100] Comparative Example 1

[0101] 1. The specific steps for preparing the electrode material in this comparative example are as follows:

[0102] (1) Same as step (1) in Example 1.

[0103] (2) Place cellulose acetate powder in a tube furnace and heat it to 400°C for 60 min in an argon atmosphere. Then heat it to 600°C for 90 min to complete the gradient carbonization process.

[0104] (3) is the same as step (4) in Example 1.

[0105] (4) is the same as step (5) in Example 1.

[0106] In the active material, the loading of Fe3O4 nanoparticles is approximately 10.2 wt%, and the specific surface area (BTE method) reaches 1063 m². 2 / g, pore volume 0.59 cm³ 3 / g; Pore size distribution: micropores (<2 nm) account for 54%, mesopores (2-50 nm) account for 36%, and macropores (>50 nm) account for 10%.

[0107] (5) is the same as step (6) in Example 1.

[0108] 2. Performance testing of high-performance low-carbon electrode materials

[0109] The test was conducted in a 6 mol / L KOH electrolyte using a three-electrode system, with high-performance low-carbon electrode material as the test electrode, Hg / HgO as the reference electrode, and a platinum sheet as the counter electrode.

[0110] The prepared supercapacitor was tested and found to have an energy density of 16.4 W h / kg and a power density of 416 W / kg, indicating a relatively low energy density. At a current density of 1 A / g, the specific capacitance of the high-performance low-carbon electrode material was 330 F / g; when the current density increased to 5 A / g, the specific capacitance was 254 F / g with a retention rate of 77.0%; when the current density increased to 10 A / g, the specific capacitance was 210 F / g with a retention rate of 63.5%, and the voltage retention rate after 24 h was 82.5%. Within the range of 10 A / g to 20 A / g, the capacitance retention rate was >50%.

[0111] After 5000 cycles at a current density of 0.5 A / g, the capacity retention is 82%. After 10000 cycles at a current density of 1 A / g, the capacity retention is 76%; internal resistance (AC impedance test) is 1.5 Ω·cm. 2 .

[0112] Comparative Example 2

[0113] 1. The specific steps for preparing the electrode material in this comparative example are as follows:

[0114] (1) Same as step (1) in Example 1.

[0115] (2) is the same as step (2) in Example 1.

[0116] (3) In an argon atmosphere, heat to 600℃ and process for 150 min to complete the carbonization process.

[0117] (4) is the same as step (4) in Example 1.

[0118] (5) is the same as step (5) in Example 1.

[0119] In the active material, the loading of Fe3O4 nanoparticles is approximately 9.5 wt%, and the specific surface area (BTE method) reaches 1000 m². 2 / g, pore volume 0.56 cm³ 3 / g; Pore size distribution: micropores (<2 nm) account for 55%, mesopores (2-50 nm) account for 33%, and macropores (>50 nm) account for 12%.

[0120] (6) is the same as step (6) in Example 1.

[0121] 2. Performance testing of high-performance low-carbon electrode materials

[0122] The test was conducted in a 6 mol / L KOH electrolyte using a three-electrode system, with high-performance low-carbon electrode material as the test electrode, Hg / HgO as the reference electrode, and a platinum sheet as the counter electrode.

[0123] The prepared supercapacitor was tested and found to have an energy density of 16.0 W h / kg and a power density of 406 W / kg, indicating a relatively low energy density. At a current density of 1 A / g, the specific capacitance of the high-performance low-carbon electrode material was 322 F / g; when the current density increased to 5 A / g, the specific capacitance was 246 F / g, with a retention rate of 76.4%; when the current density increased to 10 A / g, the specific capacitance was 202 F / g, with a retention rate of 62.7%, and the voltage retention rate after 24 h was 80.8%. Within the range of 10 A / g to 20 A / g, the capacitance retention rate was >48%.

[0124] After 5000 cycles at a current density of 0.5 A / g, the capacity retention is 80%. After 10000 cycles at a current density of 1 A / g, the capacity retention is 74%; internal resistance (AC impedance test) is 1.55 Ω·cm. 2 .

[0125] Comparative Example 3

[0126] 1. The specific steps for preparing the electrode material in this comparative example are as follows:

[0127] (1) Same as step (1) in Example 1.

[0128] (2) is the same as step (2) in Example 1.

[0129] (3) In an argon atmosphere, heat to 400℃ and process for 150 min to complete the carbonization process.

[0130] (4) is the same as step (4) in Example 1.

[0131] (5) is the same as step (5) in Example 1.

[0132] In the active material, the loading of Fe3O4 nanoparticles is approximately 9.0 wt%, and the specific surface area (BTE method) reaches 950 m². 2 / g, pore volume 0.53 cm³ 3 / g; Pore size distribution: micropores (<2 nm) account for 52%, mesopores (2-50 nm) account for 35%, and macropores (>50 nm) account for 13%.

[0133] (6) Same as step (1) of Example 1.

[0134] 2. Performance testing of high-performance low-carbon electrode materials

[0135] The test was conducted in a 6 mol / L KOH electrolyte using a three-electrode system, with high-performance low-carbon electrode material as the test electrode, Hg / HgO as the reference electrode, and a platinum sheet as the counter electrode.

[0136] The fabricated supercapacitor exhibits a high energy density of 15.6 W / kg and a power density of 395 W / kg. At a current density of 1 A / g, the specific capacitance of the high-performance low-carbon electrode material is 315 F / g; increasing the current density to 5 A / g, the specific capacitance is 238 F / g with a retention rate of 75.6%; increasing the current density to 10 A / g, the specific capacitance is 195 F / g with a retention rate of 61.9%, and the voltage retention rate after 24 h is 79%. Within the range of 10 A / g to 20 A / g, the capacitance retention rate is >46%.

[0137] After 5000 cycles at a current density of 0.5 A / g, the capacity retention is 78%. After 10000 cycles at a current density of 1 A / g, the capacity retention is 72%; internal resistance (AC impedance test) is 1.60 Ω·cm. 2 .

[0138] The above detailed embodiments describe the implementation of the present invention; however, the present invention is not limited to the specific details described in the above embodiments. Within the scope of the claims and technical concept of the present invention, various simple modifications and changes can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

Claims

1. A method for preparing a high-performance, low-carbon electrode material based on cigarette butt recycling, characterized in that, Includes the following steps: Remove impurities from cigarette butts to obtain cellulose acetate waste; The cellulose acetate waste was pre-oxidized at 240-280°C for 1-4 hours in an oxygen-containing atmosphere. In an inert atmosphere, heat to 300-400℃ for 55-65 min, then further heat to 550-600℃ for 85-95 min; Porous carbon materials are obtained by plasma treatment for 30-40 minutes under an argon atmosphere with a power of 300-400 W and an average core temperature of 50-120℃. Take porous CaCO3 micro powder and porous carbon materials and add Fe 3+ The active material is obtained by immersion in a salt solution, drying, and microwave treatment. The active material, conductive carbon black, and PVDF are added to N-methylpyrrolidone to prepare a conductive paste, which is then coated onto a current collector to prepare the high-performance low-carbon electrode material.

2. The method for preparing high-performance low-carbon electrode material based on cigarette butt recycling according to claim 1, characterized in that, The size of the cellulose acetate waste is 40-150 mesh; The first method for removing impurities from cigarette butts is to soak the cigarette butts in a 50% (v / v) aqueous ethanol solution, filter the solids, extract them with acetone, and then crush them to obtain the cellulose acetate waste. Furthermore, the mass-to-volume ratio of the cigarette butt to the 50% ethanol aqueous solution is 0.5-1.5 g / ml; The second method for removing impurities from cigarette butts is to crush the cigarette butts and then subject them to ultrasonic and microwave treatment in sequence to obtain the cellulose acetate waste. Furthermore, the ultrasonic-microwave treatment method is as follows: ultrasonic power 250-350 W, frequency 35-45 kHz, microwave power 350-450 W, temperature 55-65℃, treatment time 40-60 min; A third method for removing impurities from cigarette butts is to soak the cigarette butts in a toluene-ethanol solution, followed by ultrasonication, vacuum filtration, drying, and pulverization to obtain the cellulose acetate waste. Furthermore, the volume ratio of toluene to ethanol in the toluene-ethanol solution is (1-3):1, and the ultrasonic treatment method is to treat at 45-55℃ for 30-40 min.

3. The method for preparing high-performance low-carbon electrode material based on cigarette butt recycling according to claim 1, characterized in that, The cellulose acetate waste was pre-oxidized at 250°C for 3 hours in an oxygen-containing atmosphere.

4. The method for preparing high-performance low-carbon electrode material based on cigarette butt recycling according to claim 1, characterized in that, In an inert atmosphere, the temperature was raised to 400℃ for 60 min, and then further raised to 600℃ for 90 min.

5. The method for preparing high-performance low-carbon electrode material based on cigarette butt recycling according to claim 1, characterized in that, Porous carbon materials were obtained by plasma treatment for 35 minutes under an argon atmosphere with a power of 400 W and an average core temperature of 100℃.

6. The method for preparing high-performance low-carbon electrode material based on cigarette butt recycling according to claim 1, characterized in that, With Fe 3+ Fe in salt solution 3+ Assuming a concentration of 0.5 mol / L, the concentration of porous CaCO3 micropowder in the system is 0.05-0.15 g / ml, and the concentration of porous carbon material is 0.1 g / ml; Furthermore, the concentration of porous CaCO3 micro powder in the system is 0.1 g / ml.

7. The method for preparing high-performance low-carbon electrode material based on cigarette butt recycling according to claim 1, characterized in that, Take porous CaCO3 micro powder and porous carbon materials and add Fe 3+ Immerse in salt water solution for 1-2 hours; Furthermore, the immersion treatment time is 2 hours.

8. A high-performance, low-carbon electrode material based on cigarette butt recycling, characterized in that, It is prepared by the preparation method described in any one of claims 1-7.

9. The application of the high-performance, low-carbon electrode material based on cigarette butt recycling as described in claim 8 in the preparation of supercapacitors.

10. A supercapacitor, characterized in that, This includes electrode sheets prepared from the high-performance low-carbon electrode material as described in claim 8.